Not Working - Enable Autotarget When No Target Specified

This does not seem to be working for me as it does in other MMOs. I have this option enabled and am using attacks/abilities but I still need to tab target something for the skill/ability to fire. Shouldn't this option allow me to use an attack on a target and have that target autoselected (as in the nearest target, etc.)?

Please excuse this post if this bug has been reported, this question has already been asked or if this feature is working as intended and I'm just not understanding what it does.

Thanks!